Fluid flow restrictor



NOV. 10, 1953 I c E E Y 2,658,529

FLUID FLOW RESTRICTOR Filed June 19, 1952 AatNT Patented Nov. 18, 1953 UNITED STATES ?ATENT OFFICE Canad Application June 19, 1952, Serial No. 294,325

3 Claims.

The present invention relates to valves for the control of'fluids. It is a well known fact that when a closed valve is holding back considerable pressure and is suddenly released, the rush and turbulence of the released fluid passing through the valve results in objectionable noises. The sudden pressure, quickly building up in the previous neutral partof'the valve creates strains on the various parts and also on the line being supplied. For various'other reasons besides noise, such parts may require the pressure built up in a slower manner.

The principal object of 'the present invention is to design a fluid'flow restrictor of the valve type which, when being opened, will gradually permit increase in the velocity of the escaping fluid and so reduce the above mentioned'turbulent rush and accompanying noise, including the sudden strains.

A further object of the invention isto provide a flow restrictor which may or may not be a shutoff valve but will vary theflvelocity flow of the fluid between pie-determined limits depending on the pressure therebehind.

A further object of the invention is to obtain the above mentioned objects by anovel arrangement of flow retarding baffles which can be progressively reduced as the valve opens.

With the above important objects in view which will become more apparent as the description proceeds, the invention consists essentially in-the constructionand arrangement of parts hereinafter more particularly described, reference being had to the accompanying drawings inwhich:

Figure 1 is a sectional view through the flow restrictor. and... showing half the plunger and the control shaft in side elevation.

Figure. 2.is a horizontal sectional view taken on'the dot and dash line 2--2, Figure 1.

Figure 3 is a perspective view of the control shaft.

Figure. 4' is a perspective view of one of the liners.

In thedrawings like characters of reference indicate corresponding parts in the several figures.

The casing of :the flow restrictor is formed from three castingsnamely; a base casting l, a main casting 2, and a cover casting 3, each of which will be separately described in detail.

The base casting is of an inverted cone-shape having an inlet passage 5 centrally therethrough. The bottom presents an annular flange. 5 having holes ii therein for fastening to a supplypipe. (not shown). The upper part of the base casting carries an enlarged flange l which is secured by bolts 8 to the bottom face of the main casting 2, a suitable gasket 9 being provided therebetween. The dished upper face [0 of the base casting has an annular groove which receives a leather seat I l for a purpose laterdescribed.

The main casting 2 is of cylindrical-form which carries interior, righthand, square, screw threads [2. The lower part has an annular flange l3 which receives the base casting while the upper part carries an annular flange I i which is secured by bolts [5 to the cover casting, a gasket 13 being inbetween. The upper interior of the casting 2 is cut at a 45 angle to form an annular seat 52 the bottom part of which curves downwardly at It to cut back and form an annular baffle groove l9, just above the threads i2. At three equi-distant positions around the threads i2, vertical grooves 2U are'cut therein and the lower part of these latter grooves are outwardly stepped, as at 21. Liners 22, shown in Figure 4, are received in-the stepped'grooves in a press fit. The liners are of rectangular-shape, one side of each being outer stepped, as at 23, to mate with the stepped part iii of the grooves while the inner side of each is provided with square cross threads which are the same as the threads [2 of the main casting 2.

The cover casting 3 is of an inverted cup-shape, having a lower annular flange 25 which receives the main casting and a side offset 26 having a passageway 2'! therein which is encircled by an outer annular flange 28. This latter flange is providedwith holes 29 for fastening to an outlet pipe (not shown). The upper interior of the cover casting has a 45 sloping annular face 38 to provide a seat for a purpose later explained. The extreme upper end of the cover castingcarries a boss 3! formed with an annular flange :32 on the outside while the'centre is bored at 33 with an angular step 34;

A plunger 35 is received within the casting 2. The bottom of this plunger is cone-shaped and adapted to seat on the leather 5 i and hold fluid pressure back from the inlet passage i when the flow restrictor is shut. The centre of the plunger has a vertical hexagonal-shaped hole 36 therein which stops slightly from thebottorn. The outer sides carry right handed square threads 3'! which ride in the threads 2% of the liners 22, the thread teeth thereof face the teeth of the threads 52 of the main casting in spaced relation therefrom so that a very thin passage 35' is provided there between and for the lengths of the distances between the liners. The upper end of the plunger carries a horizontal overlying disc 39 which is secured therto by bolts 40, a gasket 4! being interposed. The periphery of this latter disc is tapered at a 45 angle on each side, as shown at 42 and 43, so that the lower taper will contact the annular seat i! when the valve is shut. When the plunger is fully screwed up on the liners the upper taper 43 will contact with the face 30 and the flow restrictor will be fully open. The disc 39 is also centrally provided with a central hexagonal hole 44 which is aligned with the hole 36.

A control shaft 45, best shown in Figure 3, has the lower part 46 thereof hexagonal in shape while the upper end carries a wheel 41 having a control handle 48. The lower end passes through the bore 33 and telescopes into the hexagonal holes 36 and 44 of the plunger. Suitable packing 49 is received in the bored hole 33 and around the shaft 45. A gland 50 also encircles the shaft and sits on the packing while an annular disc sits on the ferrule and can be pulled down thereagainst by tightening the nuts of bolts 52, which are anchored in the flanges 32, and so compress the packing. A cover plate 53 is carried by the disc 5| and holds a split washer 54 which rides in a groove 55 on the control shaft 45.

From the above description and by observing Figure 1, it will be seen that the plunger is held seated on the leather 5 I while the disc 39 is held to the seat ll, thus positively closing off any fluid from the inlet passage 4. The seating pressure is obtained through the liners and as the liners are caught in the steps 2! they cannot move upwardly. The control shaft 45 is held fluid tight by the packing 49 and as it is telescoped into the plunger with an hexagonal-shaped connection, the plunger can be screw released from the leather II by manual rotation of the wheel 41 in an anti-clockwise direction. When this occurs, the fluid escapes from the inlet passage but must pass up through all the labyrinth of passages between the threads IZ and 3! to reach the outlet passage 27 and it cannot spiral up the threads due to the three blocking liners 22. While the passages 38 between the opposing thread teeth are fairly wide in the drawings, in actual practice they will be calibrated in thousands of an inch so that the fluid, in its passage upward, will have to work past each of the baffles while passing across the relatively large spaces inbetween created by the grooves between the teeth. The total resistance of all the thread baffles will knock the head out of the fluid pressure, so to speak, and therefor a minimum quantity will move therethrough from the inlet passage to the outlet. As the control shaft is unscrewed, each turn will lessen the bafiie resistance by one thread and this in turn will increase the fluid flow until all threads are removed and the disc 39 contacts the face 30, at which time the flow restrictor will be completely open and full quantity is passing through. In this manner, the control shaft has, what might be called, a Vernier regulation over the fluid passage to regulate the velocity and as the pressure in the casing builds up slowly as the valve is opened, noise is practically eliminated. It might be mentioned at this time that, as the fluid leaves the thread baflles, it expands into the enlarged baflie groove I9 and is then restricted again as it passes through the annular space thereabove. This rather coarse bafile permits a large volume of flow but has a further quieting effect, especially when the valve is fully open. Two or more such coarse baflles may be provided if desired.

When the flow restrictor is fully open and the taper 43 of the disc 39 is in contact with the upper annular face 30, the control shaft and packing 49 is shut off from the fluid pressure in the valve casing. Accordingly, the control shaft can be drawn up by releasing the disc 5| and gland 50 and the packing 49 repaired or renewed while the flow restrictor is in service.

From the drawing in Figure 1 it will be seen that all parts of the flow restrictor are readily accessible by releasing the various bolts and nuts. Packing and leathers may be renewed quite easily or seating faces readily ground. The parts are easily made without requiring exacting work and all parts can be assembled without skilled help. The liners are inserted from the bottom of the main casting and the steps Zl prevent upward sliding movement of same under pressure. The split washer 54 insures that the control shaft will not end shift. The plunger threads are firmly held in alignment with the threads of the main casting by the liners and ample thread bearing is provided for a firm pressure of the plunger on the leather seat I l and against the seat l1. While single threads have been shown, it will be understood that any plurality of threads can be used as required by conditions under which the flow restrictor works. While a leather seat has been shown at the bottom and a metallic seat at the top and both are used, either one may be used separately to shut off the flow at any one side of the thread baffles while the other can be free, and metal or resilient material used on either. In the same way, if the construction is to be used just for variation of flow, the seats could be dispensed with and the fluid just controlled by the adjustable thread baffles in the manner explained. The device is simple in design and operation, sturdy in construction, positive in action, and wear is reduced to a minimum. It will stand up to exacting conditions for many years of useful service.

What I claim as my invention is:

l. A flow restrictor for controlling fluids, comprising: a casing; spiral threads on the interior walls of said casing; a plunger positioned within the threaded part of said casing; exterior spiral threads on said plunger, of the same pitch as said casing threads; inwardly projecting means, carried by the interior walls of said casing, for screwably receiving the threads of, and supporting, said plunger; the thread teeth of said plunger directly opposite and spaced from the teeth of said casing threads; fluid inlet and outlet pas sages in the walls of said casing, interconnected by the spacing between said plunger and casing threads; and means for rotating said plunger.

2. A flow restrictor for controlling fluids, comprising: a casing; spiral threads interiorly of said casing; liners, mounted on the inner walls of said casing, at said thread area, and in spaced relation therearound; a plunger positioned Within said casing; said plunger threadedly mounted within and on said liners with spiral threads of the same pitch as said casing threads, and with the thread teeth thereof directly opposite and spaced from the teeth of said casing threads; fluid inlet means to said casing, adjacent one end of said plunger; fluid outlet means from said casing, adjacent the opposite end of said plunger; and exterior means for rotating said plunger on said liners.

3. A flow restrictor for controlling fluids, comprising: a hollow casing having an intake passage thereto and an outlet passage therefrom; spiral threads formed on the interior walls of said cas- 5 ing, between said passages; grooves across said threads at spaced intervals therearound; toothed liners received in said grooves, with said teeth facing inwardly of said casing; a plunger; spiral threads formed on the exterior of said plunger, of 5 the same pitch as said casing threads, and screwable with the teeth of said liners; said plunger supported on said liners with the thread teeth thereof directly opposite and spaced from the teeth of said casing threads; a control shaft bearinged through said casing and telescopically received by said plunger for operable rotation thereof; and means for rotating the exterior end of said control shaft.

CHARLES A. E. HENSLEY.

6 References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Shell Oct. 7, 1913 Blaisdell June 2, 1925 Dosker Dec. 15, 1925 Bletcher Apr. 19, 1927 Ryan Dec. 10, 1929 Agee Apr. 8, 1930 

